Field of the Invention
The invention relates to a rope-suspended leader mast, comprising a lower part for accommodating a material to be pile-driven and an upper part for accommodating a diesel pile driver having a fuel feed. The leader mast is provided with at least one securing rope.
Description of the Related Art
Rope-suspended leader masts are regularly used in pile-driving locations that are difficult to access and can be reached only by way of the boom of a crane. Such locations particularly include offshore areas of use. Rope-suspended leader masts generally consist of a lower part, which forms a socket for the material to be pile-driven in and is set onto the material, which part is followed, in the upward direction, by a lattice framework that essentially has a rectangular cross-section and is provided with longitudinal guides, which are used to guide a diesel pile driver displaceably in the interior of the rope-suspended leader mast. Such a rope-suspended leader mast is described, for example, in DE 77 210 24 U1. To secure the rope-suspended leader mast, it is connected with the crane boom by way of a securing rope. In this connection, the securing rope is guided as a slack rope, wherein rope is continuously slackened during the pile-driving process, in order to prevent impairment caused by the rope.
Particularly in the case of non-homogeneous ground conditions, however, it can happen that the material to be pile-driven, and, with it, the rope-suspended leader mast, experiences an unforeseen advancing movement, thereby causing the securing rope to be tensed and the advancing force of the diesel pile driver to be applied to the crane boom. This situation can cause the boom to be severely damaged. In the worst case, tipping of the crane can actually be brought about.